Bragg grated fiber optic fluctuation sensing and monitoring system

ABSTRACT

Disclosed herein is a system, apparatus and method directed to detecting damage to an optical fiber of a medical device. The optical fiber includes core fibers including a plurality of sensors configured to (i) reflect a light signal based on received incident light, and (ii) change a characteristic of the reflected light signal based on experienced strain. The system also includes a console having memory storing logic that, when executed, causes operations of providing receiving reflected light signals of different spectral widths of the broadband incident light by one or more of the plurality of sensors, processing the reflected light signals to detect fluctuations of a portion of the optical fiber, and determining a location of the portion of the optical fiber or a defect affecting a vessel in which the portion is disposed based on the detected fluctuations. The portion may be a distal tip of the optical fiber.

PRIORITY

This application claims the benefit of priority to U.S. ProvisionalApplication No. 63/060,533, filed Aug. 3, 2020, which is incorporated byreference in its entirety into this application.

BACKGROUND

In the past, certain intravascular guidance of medical devices, such asguidewires and catheters for example, have used fluoroscopic methods fortracking tips of the medical devices and determining whether distal tipsare appropriately localized in their target anatomical structures.However, such fluoroscopic methods expose patients and their attendingclinicians to harmful X-ray radiation. Moreover, in some cases, thepatients are exposed to potentially harmful contrast media needed forthe fluoroscopic methods.

More recently, electromagnetic tracking systems have been used involvingstylets. Generally, electromagnetic tracking systems feature threecomponents: a field generator, a sensor unit and control unit. The fieldgenerator uses several coils to generate a position-varying magneticfield, which is used to establish a coordinate space. Attached to thestylet, such as near a distal end (tip) of the stylet for example, thesensor unit includes small coils in which current is induced via themagnetic field. Based on the electrical properties of each coil, theposition and orientation of the medical device may be determined withinthe coordinate space. The control unit controls the field generator andcaptures data from the sensor unit.

Although electromagnetic tracking systems avoid line-of-sight reliancein tracking the tip of a stylet while obviating radiation exposure andpotentially harmful contrast media associated with fluoroscopic methods,electromagnetic tracking systems are prone to interference. Morespecifically, since electromagnetic tracking systems depend on themeasurement of magnetic fields produced by the field generator, thesesystems are subject to electromagnetic field interference, which may becaused by the presence of many different types of consumer electronicssuch as cellular telephones. Additionally, electromagnetic trackingsystems are subject to signal drop out, depend on an external sensor,and are defined to a limited depth range.

Disclosed herein is a fiber optic shape sensing system and methodsperformed thereby where the system is configured to provide confirmationof tip placement, tracking information and/or vessel defect detectionusing optical fiber technology. Further, the system is configured todetect fluctuations of a portion of a body of implementation through oneor more core fibers, and confirm a location within the vasculature ofthe patient and/or detect a defect affecting a blood vessel (e.g.,vessel constriction, vasospasm, vessel occlusion, etc.). In someembodiments, the portion of the optical fiber may be the distal tip.Some embodiments combine the fiber optic shape sensing functionalitywith one or more of intravascular electrocardiogram (ECG) monitoring,impedance/conductance sensing, blood flow directional detection, etc.

SUMMARY

Briefly summarized, embodiments disclosed herein are directed tosystems, apparatus and methods for obtaining measurements indicatingfluctuations of a distal tip of a medical instrument (also referred toas a body of implementation), such as a catheter, a guidewire, or astylet, via a fiber optic core during advancement through a vasculatureof a patient. The systems, apparatus and methods may then furtherinclude correlation of the tip fluctuation measurements to stored data(e.g., experiential knowledge of previously measured tip fluctuations)in order to confirm a location of the distal tip of the medical deviceor detect a defect affecting a blood vessel. Although embodimentsprimarily discuss obtaining measurements indicating fluctuations of adistal tip of the medical device, the disclosure is not intended to belimited to such a particular portion of the medical device. Instead, theembodiments and methodologies described herein with respect to thedistal tip may be applied to other portions of the medical device.

More particularly, in some embodiments, the medical instrument includesoptical fiber core configured with an array of sensors (reflectivegratings), which are spatially distributed over a prescribed length ofthe core fiber to generally sense external strain on those regions ofthe core fiber occupied by the sensor. The optical fiber core isconfigured to receive broadband light from a console during advancementthrough the vasculature of a patient, where the broadband lightpropagates along at least a partial distance of the optical fiber coretoward the distal end. Given that each sensor positioned along theoptical fiber core is configured to reflect light of a different,specific spectral width, the array of sensors enables distributedmeasurements throughout the prescribed length of the multi-core opticalfiber. These distributed measurements may include wavelength shiftshaving a correlation with strain experienced by the sensor.

The reflected light from the sensors (reflective gratings) within theoptical fiber core is returned from the medical instrument forprocessing by the console. The physical state of the medical instrumentmay be ascertained based on analytics of the wavelength shifts of thereflected light. For example, the strain caused through bending of themedical instrument, and hence angular modification of the optical fibercore, causes different degrees of deformation. The different degrees ofdeformation alter the shape of the sensors (reflective grating)positioned on the optical fiber core, which may cause variations(shifts) in the wavelength of the reflected light from the sensorspositioned on the optical fiber core. The optical fiber core maycomprise a single optical fiber, or a plurality of optical fibers (inwhich case, the optical fiber core is referred to as a “multi-coreoptical fiber”).

As used herein, the term “core fiber,” generally refers to a singleoptical fiber core disposed within a medical device. Thus, discussion ofa core fiber refers to single optical fiber core and discussion of amulti-core optical fiber refers to a plurality of core fibers. Variousembodiments discussed below to detection of the health (and particularlythe damage) that occurs in each of an optical fiber core of medicaldevice including (i) a single core fiber, and (ii) a plurality of corefibers.

Specific embodiments of the disclosure include utilization of a medicalinstrument, such as a stylet, featuring a multi-core optical fiber and aconductive medium that collectively operate for tracking placement witha body of a patient of the stylet or another medical device (such as acatheter) in which the stylet is disposed. In lieu of a stylet, aguidewire may be utilized. For convenience, embodiments are generallydiscussed where the optical fiber core is disposed within a stylet;however, the disclosure is not intended to be so limited as thefunctionality involving detection of the health of an optical fiber coredisclosed herein may be implemented regardless of the medical device inwhich the optical fiber core is disposed.

In some embodiments, the optical fiber core of a stylet is configured toreturn information for use in identifying its physical state (e.g.,shape length, shape, and/or form) of (i) a portion of the stylet (e.g.,tip, segment of stylet, etc.) or a portion of a catheter inclusive of atleast a portion of the stylet (e.g., tip, segment of catheter, etc.) or(ii) the entirety or a substantial portion of the stylet or catheterwithin the body of a patient (hereinafter, described as the “physicalstate of the stylet” or the “physical state of the catheter”). Accordingto one embodiment of the disclosure, the returned information may beobtained from reflected light signals of different spectral widths,where each reflected light signal corresponds to a portion of broadbandincident light propagating along a core of the multi-core optical fiber(hereinafter, “core fiber”) that is reflected back over the core fiberby a particular sensor located on the core fiber. One illustrativeexample of the returned information may pertain to a change in signalcharacteristics of the reflected light signal returned from the sensor,where wavelength shift is correlated to (mechanical) strain on the corefiber.

In some embodiments, the core fiber utilizes a plurality of sensors andeach sensor is configured to reflect a different spectral range of theincident light (e.g., different light frequency range). Based on thetype and degree of strain asserted on each core fiber, the sensorsassociated with that core fiber may alter (shift) the wavelength of thereflected light to convey the type and degree of stain on that corefiber at those locations of the stylet occupied by the sensors. Thesensors are spatially distributed at various locations of the core fiberbetween a proximal end and a distal end of the stylet so that shapesensing of the stylet may be conducted based on analytics of thewavelength shifts. Herein, the shape sensing functionality is pairedwith the ability to simultaneously pass an electrical signal through thesame member (stylet) through conductive medium included as part of thestylet.

More specifically, in some embodiments each core fiber of the multi-coreoptical fiber is configured with an array of sensors, which arespatially distributed over a prescribed length of the core fiber togenerally sense external strain those regions of the core fiber occupiedby the sensor. Given that each sensor positioned along the same corefiber is configured to reflect light of a different, specific spectralwidth, the array of sensors enables distributed measurements throughoutthe prescribed length of the multi-core optical fiber. These distributedmeasurements may include wavelength shifts having a correlation withstrain experienced by the sensor.

According to one embodiment of the disclosure, each sensor may operateas a reflective grating such as a fiber Bragg grating (FBG), namely anintrinsic sensor corresponding to a permanent, periodic refractive indexchange inscribed into the core fiber. Stated differently, the sensoroperates as a light reflective mirror for a specific spectral width(e.g., a specific wavelength or specific range of wavelengths). As aresult, as broadband incident light is supplied by an optical lightsource and propagates through a particular core fiber, upon reaching afirst sensor of the distributed array of sensors for that core fiber,light of a prescribed spectral width associated with the first sensor isreflected back to an optical receiver within a console, including adisplay and the optical light source. The remaining spectrum of theincident light continues propagation through the core fiber toward adistal end of the stylet. The remaining spectrum of the incident lightmay encounter other sensors from the distributed array of sensors, whereeach of these sensors is fabricated to reflect light with differentspecific spectral widths to provide distributed measurements, asdescribed above.

During operation, multiple light reflections (also referred to as“reflected light signals”) are returned to the console from each of theplurality of core fibers of the multi-core optical fiber. Each reflectedlight signal may be uniquely associated with a different spectral width.Information associated with the reflected light signals may be used todetermine a three-dimensional representation of the physical state ofthe stylet within the body of a patient. Herein, the core fibers arespatially separated with the cladding of the multi-mode optical fiberand each core fiber is configured to separately return light ofdifferent spectral widths (e.g., specific light wavelength or a range oflight wavelengths) reflected from the distributed array of sensorsfabricated in each of the core fibers. A comparison of detected shiftsin wavelength of the reflected light returned by a center core fiber(operating as a reference) and the surrounding, periphery core fibersmay be used to determine the physical state of the stylet.

During vasculature insertion and advancement of the catheter, theclinician may rely on the console to visualize a current physical state(e.g., shape) of a catheter guided by the stylet to avoid potential pathdeviations. As the periphery core fibers reside at spatially differentlocations within the cladding of the multi-mode optical fiber, changesin angular orientation (such as bending with respect to the center corefiber, etc.) of the stylet imposes different types (e.g., compression ortension) and degrees of strain on each of the periphery core fibers aswell as the center core fiber. The different types and/or degree ofstrain may cause the sensors of the core fibers to apply differentwavelength shifts, which can be measured to extrapolate the physicalstate of the stylet (catheter).

Embodiments of the disclosure may include a combination of one or moreof the methodologies to determine the location of a distal tip of a bodyof implementation (e.g., an introducer wire, a guidewire, a styletwithin a needle, a needle with fiber optic inlayed into the cannula, astylet configured for use with a catheter, an optical fiber between aneedle and a catheter, and/or an optical fiber integrated into acatheter) and/or various defects of a vessel of a patient through whichthe body of implementation is advancing. For example, some embodimentsare directed to detection of the distal tip of the body ofimplementation advancing through the Super Vena Cava (SVC) toward theright atrium of the patient's heart, where the detection may be based atleast in part on detecting fluctuations in the tip of the body ofimplementation and correlated against expected fluctuations caused bythe rhythm of the heart. Other embodiments are directed to detection ofdefects in a vessel through which the body of implementation isadvancing through detection of tip fluctuations of the body ofimplementation and correlating such expected fluctuations for thelocation of the tip of the body of implementation and/or knownfluctuations for certain defects. Examples of defects that may bedetected through embodiments discussed herein include, but are notlimited or restricted to, vessel constriction, a vasospasm, and anocclusion in the vessel.

For instance, certain embodiments include the logic configured toperform run-time analytics, heuristics and/or machine-learningtechniques to correlate detected fluctuations of the distal tip of thebody of implementation with previously detected tip fluctuations (e.g.,experiential knowledge).

Further embodiments of the disclosure may include integration with anycombination of the following, as will be discussed below:electrocardiogram (ECG) signaling systems, ultrasound systems, fiberoptic shape sensing techniques, tip location techniques, tipconfirmation techniques, impedance/conductance sensing, confirmation ofcatheter advancement techniques (e.g., a fluctuating body ofimplementation stops/changes in fluctuation as catheter tip is advancedover this body), blood pressure, and/or blood flow directionidentification. It should be noted that embodiments containing anoptical fiber core either advancing in, or integrated with, a body ofimplementation and void of other detection systems may be compatible foruse with a magnetic resonance imaging system.

In some embodiments, as an optic fiber is relatively flexible, the bodyof implementation may be reinforced through, for example, one or morelayers of reinforcing or layering material, where such reinforcement mayprovide a degree of stiffness to the length of the body ofimplementation. In some such embodiments, the amount of reinforcementmay vary along the length of the body of implementation such that degreeof stiffness varies accordingly. For example, in one exemplaryembodiment, the amount of reinforcement provided may be a first amountfor a first portion of the body of implementation and a second, lessamount of a second portion (e.g., where the second portion is the distaltip). In such an example, the level of stiffness would be less at thedistal tip than for the remaining length of the body of implementation.Such an embodiment would provide for greater flexibility at the distaltip thereby enabling a greater range of motion motivated by blood flow,turbulence, etc. The greater range of motion may be measured by theoptic fiber or other sensors as described herein. As a result, such anexemplary embodiment may be better suited to measure movement at thedistal tip of the body of implementation than embodiments having auniform stiffness along the length of the body of implementation.

Additionally, the body of implementation may include one or moreprotrusions that extend from the body of implementation that areconfigured to amplify the forces being experienced by the body ofimplementation. In some embodiments, the protrusions may be deployableduring advancement of the body of implementation in the vasculature ofthe patient. For instance, logic of the console may be configured toreceive user input initiating deployment such that, in response, thelogic transmits a signal that causes deployment (e.g., a flap may beextended from body of implementation in a direction substantiallyperpendicular to the direction of the anticipated (or detected) force ormotion. In such embodiments, the protrusions may experience greaterfluctuations with each passing volume of blood, vessel spasm, etc., ascompared to a body of implementation without such protrusions.

Some embodiments of the disclosure are directed to a medical devicesystem for detecting fluctuation using optical fiber technology of amedical device. The system may comprise the medical device comprising anoptical fiber having one or more of core fibers, each of the one or morecore fibers including a plurality of sensors distributed along alongitudinal length of a corresponding core fiber and each sensor of theplurality of sensors being configured to (i) reflect a light signal of adifferent spectral width based on received incident light, and (ii)change a characteristic of the reflected light signal based on strainexperienced by the optical fiber. The system may further comprise aconsole including one or more processors and a non-transitorycomputer-readable medium having stored thereon logic, when executed bythe one or more processors, causes operations including providing abroadband incident light signal to the optical fiber, receivingreflected light signals of different spectral widths of the broadbandincident light by one or more of the plurality of sensors, processingthe reflected light signals associated with the one or more of corefibers to detect fluctuations of a distal tip of the optical fiber, anddetermining a location of the distal tip of the optical fiber or adefect affecting a vessel in which the distal tip is disposed based onthe detected fluctuations.

In some embodiments, the optical fiber is a single-core optical fiber.In alternative embodiments, the optical fiber is a multi-core opticalfiber including a plurality of core fibers. In some embodiments, thedefect is one of a constriction of the vessel, a vasospasm of thevessel, or an occlusion in the vessel.

In certain embodiments, the determining performed by the logic includescorrelating the reflected light signals with previously obtainedreflected light signals to identify the location of the distal tip ofthe optical fiber or the defect affecting a vessel, and determiningwhether a correlation result is above a first threshold. In someembodiments, the correlating is performed through machine-learningtechniques. In certain embodiments, determining the location of thedistal tip of the optical fiber includes obtaining electrocardiogram(ECG) signals, correlating the ECG signals with the detectedfluctuations to identify whether the detected fluctuations includemovements in accordance with a rhythmic pattern of the ECG signals, anddetermining whether a correlation result is above a first threshold.

In some embodiments, the medical device is one of an introducer wire, aguidewire, a stylet, a stylet within a needle, a needle with the opticalfiber inlayed into a cannula of the needle or a catheter with theoptical fiber inlayed into one or more walls of the catheter. Further,in some embodiments, each of the plurality of sensors is a reflectivegrating, where each reflective grating alters its reflected light signalby applying a wavelength shift dependent on a strain experienced by thereflective grating. Some embodiments may include logic that, whenexecuted by the one or more processors, causes further operationsincluding generating an alert indicating an existence of the defect. Incertain embodiments, the alert includes an indication of a location ofthe defect.

Some embodiments of the disclosure are directed to a method for placinga medical device into a body of a patient, the method comprisingproviding a broadband incident light signal to an optical fiber includedwithin the medical device, wherein the optical fiber includes a one ormore of core fibers, each of the one or more of core fibers including aplurality of reflective gratings distributed along a longitudinal lengthof a corresponding core fiber and each of the plurality of reflectivegratings being configured to (i) reflect a light signal of a differentspectral width based on received incident light, and (ii) change acharacteristic of the reflected light signal based on strain experiencedby the optical fiber, receiving reflected light signals of differentspectral widths of the broadband incident light by one or more of theplurality of sensors, processing the reflected light signals associatedwith the one or more of core fibers to detect fluctuations of a distaltip of the optical fiber, and determining a location of the distal tipof the optical fiber or a defect affecting a vessel in which the distaltip is disposed based on the detected fluctuations.

In some embodiments, the optical fiber is a single-core optical fiber.In alternative embodiments, the optical fiber is a multi-core opticalfiber including a plurality of core fibers. In some embodiments, thedefect is one of a constriction of the vessel, a vasospasm of thevessel, or an occlusion in the vessel.

In certain embodiments, the determining performed by the logic includescorrelating the reflected light signals with previously obtainedreflected light signals to identify the location of the distal tip ofthe optical fiber or the defect affecting a vessel, and determiningwhether a correlation result is above a first threshold. In someembodiments, the correlating is performed through machine-learningtechniques. In certain embodiments, determining the location of thedistal tip of the optical fiber includes obtaining electrocardiogram(ECG) signals, correlating the ECG signals with the detectedfluctuations to identify whether the detected fluctuations includemovements in accordance with a rhythmic pattern of the ECG signals, anddetermining whether a correlation result is above a first threshold.

In some embodiments, the medical device is one of an introducer wire, aguidewire, a stylet, a stylet within a needle, a needle with the opticalfiber inlayed into a cannula of the needle or a catheter with theoptical fiber inlayed into one or more walls of the catheter. Further,in some embodiments, each of the plurality of sensors is a reflectivegrating, where each reflective grating alters its reflected light signalby applying a wavelength shift dependent on a strain experienced by thereflective grating. Some embodiments may include logic that, whenexecuted by the one or more processors, causes further operationsincluding generating an alert indicating an existence of the defect. Incertain embodiments, the alert includes an indication of a location ofthe defect.

Yet other embodiments of the disclosure are directed a non-transitorycomputer-readable medium having stored thereon logic that, when executedby one or more processors, causes operations including providing abroadband incident light signal to an optical fiber included within themedical device, wherein the optical fiber includes a one or more of corefibers, each of the one or more of core fibers including a plurality ofreflective gratings distributed along a longitudinal length of acorresponding core fiber and each of the plurality of reflectivegratings being configured to (i) reflect a light signal of a differentspectral width based on received incident light, and (ii) change acharacteristic of the reflected light signal based on strain experiencedby the optical fiber, receiving reflected light signals of differentspectral widths of the broadband incident light by one or more of theplurality of sensors, processing the reflected light signals associatedwith the one or more of core fibers to detect fluctuations of a distaltip of the optical fiber, and determining a location of the distal tipof the optical fiber or a defect affecting a vessel in which the distaltip is disposed based on the detected fluctuations.

In some embodiments, the optical fiber is a single-core optical fiber.In alternative embodiments, the optical fiber is a multi-core opticalfiber including a plurality of core fibers. In some embodiments, thedefect is one of a constriction of the vessel, a vasospasm of thevessel, or an occlusion in the vessel.

In certain embodiments, the determining performed by the logic includescorrelating the reflected light signals with previously obtainedreflected light signals to identify the location of the distal tip ofthe optical fiber or the defect affecting a vessel, and determiningwhether a correlation result is above a first threshold. In someembodiments, the correlating is performed through machine-learningtechniques. In certain embodiments, determining the location of thedistal tip of the optical fiber includes obtaining electrocardiogram(ECG) signals, correlating the ECG signals with the detectedfluctuations to identify whether the detected fluctuations includemovements in accordance with a rhythmic pattern of the ECG signals, anddetermining whether a correlation result is above a first threshold.

In some embodiments, the medical device is one of an introducer wire, aguidewire, a stylet, a stylet within a needle, a needle with the opticalfiber inlayed into a cannula of the needle or a catheter with theoptical fiber inlayed into one or more walls of the catheter. Further,in some embodiments, each of the plurality of sensors is a reflectivegrating, where each reflective grating alters its reflected light signalby applying a wavelength shift dependent on a strain experienced by thereflective grating. Some embodiments may include logic that, whenexecuted by the one or more processors, causes further operationsincluding generating an alert indicating an existence of the defect. Incertain embodiments, the alert includes an indication of a location ofthe defect.

These and other features of the concepts provided herein will becomemore apparent to those of skill in the art in view of the accompanyingdrawings and following description, which disclose particularembodiments of such concepts in greater detail.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure are illustrated by way of example and notby way of limitation in the figures of the accompanying drawings, inwhich like references indicate similar elements and in which:

FIG. 1A is an illustrative embodiment of a medical instrument monitoringsystem including a medical instrument with optic shape sensing and fiberoptic-based oximetry capabilities in accordance with some embodiments;

FIG. 1B is an alternative illustrative embodiment of the medicalinstrument monitoring system 100 in accordance with some embodiments;

FIG. 2 is an exemplary embodiment of a structure of a section of themulti-core optical fiber included within the stylet 120 of FIG. 1A inaccordance with some embodiments;

FIG. 3A is a first exemplary embodiment of the stylet of FIG. 1Asupporting both an optical and electrical signaling in accordance withsome embodiments;

FIG. 3B is a cross sectional view of the stylet of FIG. 3A in accordancewith some embodiments;

FIG. 4A is a second exemplary embodiment of the stylet of FIG. 1B inaccordance with some embodiments;

FIG. 4B is a cross sectional view of the stylet of FIG. 4A in accordancewith some embodiments;

FIG. 5A is an elevation view of a first illustrative embodiment of acatheter including integrated tubing, a diametrically disposed septum,and micro-lumens formed within the tubing and septum in accordance withsome embodiments;

FIG. 5B is a perspective view of the first illustrative embodiment ofthe catheter of FIG. 5A including core fibers installed within themicro-lumens in accordance with some embodiments;

FIGS. 6A-6B are flowcharts of the methods of operations conducted by themedical instrument monitoring system of FIGS. 1A-1B to achieve optic 3Dshape sensing in accordance with some embodiments;

FIG. 7 is an exemplary embodiment of the medical instrument monitoringsystem of FIG. 1A during operation and insertion of the catheter into apatient in accordance with some embodiments;

FIG. 8A is a detailed view of a stylet disposed within the Superior VenaCava (SVC) advancing toward the right atrium of a patient in accordancewith some embodiments;

FIG. 8B is side elevation view of a stylet advancing through a vessel ofthe vasculature of a patient toward a point of constriction in thevessel in accordance with some embodiments;

FIG. 8C is side elevation view of a stylet advancing through a vessel ofthe vasculature of a patient toward a vasospasm affecting the vessel inaccordance with some embodiments; and

FIG. 8D is side elevation view of a stylet advancing through a vessel ofthe vasculature of a patient toward an occlusion in the vessel inaccordance with some embodiments.

DETAILED DESCRIPTION

Before some particular embodiments are disclosed in greater detail, theparticular embodiments disclosed herein do not limit the scope of theconcepts provided herein. It should also be understood that a particularembodiment disclosed herein can have features that can be readilyseparated from the particular embodiment and optionally combined with orsubstituted for features of any of a number of other embodimentsdisclosed herein.

Regarding terms used herein, it should also be understood the terms arefor the purpose of describing some particular embodiments, and the termsdo not limit the scope of the concepts provided herein. Ordinal numbers(e.g., first, second, third, etc.) are generally used to distinguish oridentify different features or steps in a group of features or steps,and do not supply a serial or numerical limitation. For example,“first,” “second,” and “third” features or steps need not necessarilyappear in that order, and the particular embodiments including suchfeatures or steps need not necessarily be limited to the three featuresor steps. Labels such as “left,” “right,” “top,” “bottom,” “front,”“back,” and the like are used for convenience and are not intended toimply, for example, any particular fixed location, orientation, ordirection. Instead, such labels are used to reflect, for example,relative location, orientation, or directions. Singular forms of “a,”“an,” and “the” include plural references unless the context clearlydictates otherwise.

With respect to “proximal,” a “proximal portion” or a “proximal endportion” of, for example, a probe disclosed herein includes a portion ofthe probe intended to be near a clinician when the probe is used on apatient. Likewise, a “proximal length” of, for example, the probeincludes a length of the probe intended to be near the clinician whenthe probe is used on the patient. A “proximal end” of, for example, theprobe includes an end of the probe intended to be near the clinicianwhen the probe is used on the patient. The proximal portion, theproximal end portion, or the proximal length of the probe can includethe proximal end of the probe; however, the proximal portion, theproximal end portion, or the proximal length of the probe need notinclude the proximal end of the probe. That is, unless context suggestsotherwise, the proximal portion, the proximal end portion, or theproximal length of the probe is not a terminal portion or terminallength of the probe.

With respect to “distal,” a “distal portion” or a “distal end portion”of, for example, a probe disclosed herein includes a portion of theprobe intended to be near or in a patient when the probe is used on thepatient. Likewise, a “distal length” of, for example, the probe includesa length of the probe intended to be near or in the patient when theprobe is used on the patient. A “distal end” of, for example, the probeincludes an end of the probe intended to be near or in the patient whenthe probe is used on the patient. The distal portion, the distal endportion, or the distal length of the probe can include the distal end ofthe probe; however, the distal portion, the distal end portion, or thedistal length of the probe need not include the distal end of the probe.That is, unless context suggests otherwise, the distal portion, thedistal end portion, or the distal length of the probe is not a terminalportion or terminal length of the probe.

The term “logic” may be representative of hardware, firmware or softwarethat is configured to perform one or more functions. As hardware, theterm logic may refer to or include circuitry having data processingand/or storage functionality. Examples of such circuitry may include,but are not limited or restricted to a hardware processor (e.g.,microprocessor, one or more processor cores, a digital signal processor,a programmable gate array, a microcontroller, an application specificintegrated circuit “ASIC”, etc.), a semiconductor memory, orcombinatorial elements.

Additionally, or in the alternative, the term logic may refer to orinclude software such as one or more processes, one or more instances,Application Programming Interface(s) (API), subroutine(s), function(s),applet(s), servlet(s), routine(s), source code, object code, sharedlibrary/dynamic link library (dll), or even one or more instructions.This software may be stored in any type of a suitable non-transitorystorage medium, or transitory storage medium (e.g., electrical, optical,acoustical or other form of propagated signals such as carrier waves,infrared signals, or digital signals). Examples of a non-transitorystorage medium may include, but are not limited or restricted to aprogrammable circuit; non-persistent storage such as volatile memory(e.g., any type of random-access memory “RAM”); or persistent storagesuch as non-volatile memory (e.g., read-only memory “ROM”, power-backedRAM, flash memory, phase-change memory, etc.), a solid-state drive, harddisk drive, an optical disc drive, or a portable memory device. Asfirmware, the logic may be stored in persistent storage.

Referring to FIG. 1A, an illustrative embodiment of a medical instrumentmonitoring system including a medical instrument with optic shapesensing and fiber optic-based oximetry capabilities is shown inaccordance with some embodiments. As shown, the system 100 generallyincludes a console 110 and a stylet assembly 119 communicatively coupledto the console 110. For this embodiment, the stylet assembly 119includes an elongate probe (e.g., stylet) 120 on its distal end 122 anda console connector 133 on its proximal end 124, where the stylet 120 isconfigured to advance within a patient vasculature either through, or inconjunction with, a catheter 195. The console connector 133 enables thestylet assembly 119 to be operably connected to the console 110 via aninterconnect 145 including one or more optical fibers 147 (hereinafter,“optical fiber(s)”) and a conductive medium terminated by a singleoptical/electric connector 146 (or terminated by dual connectors).Herein, the connector 146 is configured to engage (mate) with theconsole connector 133 to allow for the propagation of light between theconsole 110 and the stylet assembly 119 as well as the propagation ofelectrical signals from the stylet 120 to the console 110.

An exemplary implementation of the console 110 includes a processor 160,a memory 165, a display 170 and optical logic 180, although it isappreciated that the console 110 can take one of a variety of forms andmay include additional components (e.g., power supplies, ports,interfaces, etc.) that are not directed to aspects of the disclosure. Anillustrative example of the console 110 is illustrated in U.S.Publication No. 2019/0237902, the entire contents of which areincorporated by reference herein. The processor 160, with access to thememory 165 (e.g., non-volatile memory or non-transitory,computer-readable medium), is included to control functionality of theconsole 110 during operation. As shown, the display 170 may be a liquidcrystal diode (LCD) display integrated into the console 110 and employedas a user interface to display information to the clinician, especiallyduring a catheter placement procedure (e.g., cardiac catheterization).In another embodiment, the display 170 may be separate from the console110. Although not shown, a user interface is configured to provide usercontrol of the console 110.

For both embodiments, the content depicted by the display 170 may changeaccording to which mode the stylet 120 is configured to operate:optical, TLS, ECG, or another modality. In TLS mode, the contentrendered by the display 170 may constitute a two-dimensional (2D) orthree-dimensional (3D) representation of the physical state (e.g.,length, shape, form, and/or orientation) of the stylet 120 computed fromcharacteristics of reflected light signals 150 returned to the console110. The reflected light signals 150 constitute light of a specificspectral width of broadband incident light 155 reflected back to theconsole 110. According to one embodiment of the disclosure, thereflected light signals 150 may pertain to various discrete portions(e.g., specific spectral widths) of broadband incident light 155transmitted from and sourced by the optical logic 180, as describedbelow

According to one embodiment of the disclosure, an activation control126, included on the stylet assembly 119, may be used to set the stylet120 into a desired operating mode and selectively alter operability ofthe display 170 by the clinician to assist in medical device placement.For example, based on the modality of the stylet 120, the display 170 ofthe console 110 can be employed for optical modality-based guidanceduring catheter advancement through the vasculature or TLS modality todetermine the physical state (e.g., length, form, shape, orientation,etc.) of the stylet 120. In one embodiment, information from multiplemodes, such as optical, TLS or ECG for example, may be displayedconcurrently (e.g., at least partially overlapping in time).

Referring still to FIG. 1A, the optical logic 180 is configured tosupport operability of the stylet assembly 119 and enable the return ofinformation to the console 110, which may be used to determine thephysical state associated with the stylet 120 along with monitoredelectrical signals such as ECG signaling via an electrical signalinglogic 181 that supports receipt and processing of the receivedelectrical signals from the stylet 120 (e.g., ports, analog-to-digitalconversion logic, etc.). The physical state of the stylet 120 may bebased on changes in characteristics of the reflected light signals 150received at the console 110 from the stylet 120. The characteristics mayinclude shifts in wavelength caused by strain on certain regions of thecore fibers integrated within an optical fiber core 135 positionedwithin or operating as the stylet 120, as shown below. As discussedherein, the optical fiber core 135 may be comprised of core fibers 137₁-137 _(M) (M=1 for a single core, and M≥2 for a multi-core), where thecore fibers 137 ₁-137 _(M) may collectively be referred to as corefiber(s) 137. Unless otherwise specified or the instant embodimentrequires an alternative interpretation, embodiments discussed hereinwill refer to a multi-core optical fiber 135. From informationassociated with the reflected light signals 150, the console 110 maydetermine (through computation or extrapolation of the wavelengthshifts) the physical state of the stylet 120, and that of the catheter195 configured to receive the stylet 120.

According to one embodiment of the disclosure, as shown in FIG. 1A, theoptical logic 180 may include a light source 182 and an optical receiver184. The light source 182 is configured to transmit the incident light155 (e.g., broadband) for propagation over the optical fiber(s) 147included in the interconnect 145, which are optically connected to themulti-core optical fiber core 135 within the stylet 120. In oneembodiment, the light source 182 is a tunable swept laser, althoughother suitable light sources can also be employed in addition to alaser, including semi-coherent light sources, LED light sources, etc.

The optical receiver 184 is configured to: (i) receive returned opticalsignals, namely reflected light signals 150 received from opticalfiber-based reflective gratings (sensors) fabricated within each corefiber of the multi-core optical fiber 135 deployed within the stylet120, and (ii) translate the reflected light signals 150 into reflectiondata (from repository 192), namely data in the form of electricalsignals representative of the reflected light signals includingwavelength shifts caused by strain. The reflected light signals 150associated with different spectral widths may include reflected lightsignals 151 provided from sensors positioned in the center core fiber(reference) of the multi-core optical fiber 135 and reflected lightsignals 152 provided from sensors positioned in the periphery corefibers of the multi-core optical fiber 135, as described below. Herein,the optical receiver 184 may be implemented as a photodetector, such asa positive-intrinsic-negative “PIN” photodiode, avalanche photodiode, orthe like.

As shown, both the light source 182 and the optical receiver 184 areoperably connected to the processor 160, which governs their operation.Also, the optical receiver 184 is operably coupled to provide thereflection data (from repository 192) to the memory 165 for storage andprocessing by reflection data classification logic 190. The reflectiondata classification logic 190 may be configured to: (i) identify whichcore fibers pertain to which of the received reflection data (fromrepository 192) and (ii) segregate the reflection data stored with arepository 192 provided from reflected light signals 150 pertaining tosimilar regions of the stylet 120 or spectral widths into analysisgroups. The reflection data for each analysis group is made available toshape sensing logic 194 for analytics.

According to one embodiment of the disclosure, the shape sensing logic194 is configured to compare wavelength shifts measured by sensorsdeployed in each periphery core fiber at the same measurement region ofthe stylet 120 (or same spectral width) to the wavelength shift at acenter core fiber of the multi-core optical fiber 135 positioned alongcentral axis and operating as a neutral axis of bending. From theseanalytics, the shape sensing logic 194 may determine the shape the corefibers have taken in 3D space and may further determine the currentphysical state of the catheter 195 in 3D space for rendering on thedisplay 170.

According to one embodiment of the disclosure, the shape sensing logic194 may generate a rendering of the current physical state of the stylet120 (and potentially the catheter 195), based on heuristics or run-timeanalytics. For example, the shape sensing logic 194 may be configured inaccordance with machine-learning techniques to access a data store(library) with pre-stored data (e.g., images, etc.) pertaining todifferent regions of the stylet 120 (or catheter 195) in which reflectedlight from core fibers have previously experienced similar or identicalwavelength shifts. From the pre-stored data, the current physical stateof the stylet 120 (or catheter 195) may be rendered. Alternatively, asanother example, the shape sensing logic 194 may be configured todetermine, during run-time, changes in the physical state of each regionof the multi-core optical fiber 135 based on at least: (i) resultantwavelength shifts experienced by different core fibers within theoptical fiber 135, and (ii) the relationship of these wavelength shiftsgenerated by sensors positioned along different periphery core fibers atthe same cross-sectional region of the multi-core optical fiber 135 tothe wavelength shift generated by a sensor of the center core fiber atthe same cross-sectional region. It is contemplated that other processesand procedures may be performed to utilize the wavelength shifts asmeasured by sensors along each of the core fibers within the multi-coreoptical fiber 135 to render appropriate changes in the physical state ofthe stylet 120 (and/or catheter 195), especially to enable guidance ofthe stylet 120, when positioned at a distal tip of the catheter 195,within the vasculature of the patient and at a desired destinationwithin the body.

The console 110 may further include electrical signaling logic 181,which is positioned to receive one or more electrical signals from thestylet 120. The stylet 120 is configured to support both opticalconnectivity as well as electrical connectivity. The electricalsignaling logic 181 receives the electrical signals (e.g., ECG signals)from the stylet 120 via the conductive medium. The electrical signalsmay be processed by electrical signal logic 196, executed by theprocessor 160, to determine ECG waveforms for display.

Additionally, the console 110 includes a fluctuation logic 198 that isconfigured to analyze at least a subset of the wavelength shiftsmeasured by sensors deployed in each of the core fibers 137. Inparticular, the fluctuation logic 198 is configured to analyzewavelength shifts measured by sensors of core fibers 137, where suchcorresponds to an analysis of the fluctuation of the distal tip of thestylet 120 (or “tip fluctuation analysis”). In some embodiments, thefluctuation logic 198 analyzes the wavelength shifts measured by sensorsat a distal end of the core fibers 137. The tip fluctuation analysisincludes at least a correlation of detected movements of the distal tipof the stylet 120 (or other medical device or instrument) withexperiential knowledge comprising previously detected movements(fluctuations), and optionally, other current measurements such as ECGsignals. The experiential knowledge may include previously detectedmovements in various locations within the vasculature (e.g., SVC,Inferior Vena Cava (IVC), right atrium, azygos vein, other blood vesselssuch as arteries and veins) under normal, healthy conditions and in thepresence of defects (e.g., vessel constriction, vasospasm, vesselocclusion, etc.). Thus, the tip fluctuation analysis may result in aconfirmation of tip location and/or detection of a defect affecting ablood vessel.

It should be noted that the fluctuation logic 198 need not perform thesame analyses as the shape sensing logic 194. For instance, the shapesensing logic 194 determines a 3D shape of the stylet 120 by comparingwavelength shifts in outer core fibers of a multi-core optical fiber toa center, reference core fiber. The fluctuation logic 198 may insteadcorrelate the wavelength shifts to previously measured wavelength shiftsand optionally other current measurements without distinguishing betweenwavelength shifts of outer core fibers and a center, reference corefiber as the tip fluctuation analysis need not consider direction orshape within a 3D space.

In some embodiments, e.g., those directed at tip location confirmation,the analysis of the fluctuation logic 198 may utilize electrical signals(e.g., ECG signals) measured by the electrical signaling logic 181. Forexample, the fluctuation logic 198 may compare the movements of asubsection of the stylet 120 (e.g., the distal tip) with electricalsignals indicating impulses of the heart (e.g., the heartbeat). Such acomparison may reveal whether the distal tip is within the SVC or theright atrium based on how closely the movements correspond to a rhythmicheartbeat.

In various embodiments, a display and/or alert may be generated based onthe fluctuation analysis. For instance, the fluctuation logic 198 maygenerate a graphic illustrating the detected fluctuation compared topreviously detected tip fluctuations and/or the anatomical movements ofthe patient body such as rhythmic pulses of the heart and/or expandingand contracting of the lungs. In one embodiment, such a graphic mayinclude a dynamic visualization of the present medical device moving inaccordance with the detected fluctuations adjacent to a secondarymedical device moving in accordance with previously detected tipfluctuations. In some embodiments, the location of a subsection of themedical device may be obtained from the shape sensing logic 194 and thedynamic visualization may be location-specific (e.g., such that thepreviously detected fluctuations illustrate expected fluctuations forthe current location of the subsection). In alternative embodiments, thedynamic visualization may illustrate a comparison of the dynamicmovements of the subsection to one or more subsections moving inaccordance with previously detected fluctuations of one or more defectsaffecting the blood vessel.

According to one embodiment of the disclosure, the fluctuation logic 198may determine whether movements of one or more subsections of the stylet120 indicate a location of a particular subsection of the stylet 120 ora defect affecting a blood vessel and, as a result, of the catheter 195,based on heuristics or run-time analytics. For example, the fluctuationlogic 198 may be configured in accordance with machine-learningtechniques to access a data store (library) with pre-stored data (e.g.,experiential knowledge of previously detected tip fluctuation data,etc.) pertaining to different regions (subsections) of the stylet 120.Specifically, such an embodiment may include processing of amachine-learning model trained using the experiential knowledge, wherethe detected fluctuations serve as input to the trained model andprocessing of the trained model results in a determination as to howclosely the detected fluctuations correlate to one or more locationswithin the vasculature of the patient and/or one or more defectsaffecting a blood vessel.

In some embodiments, the fluctuation logic 198 may be configured todetermine, during run-time, whether movements of one or more subsectionsof the stylet 120 (and the catheter 195) indicate a location of aparticular subsection of the stylet 120 or a defect affecting a bloodvessel, based on at least (i) resultant wavelength shifts experienced bythe core fibers 137 within the one or more subsections, and (ii) thecorrelation of these wavelength shifts generated by sensors positionedalong different core fibers at the same cross-sectional region of thestylet 120 (or the catheter 195) to previously detected wavelengthshifts generated by corresponding sensors in a core fiber at the samecross-sectional region. It is contemplated that other processes andprocedures may be performed to utilize the wavelength shifts as measuredby sensors along each of the core fibers 137 to render appropriatemovements in the distal tip of the stylet 120 and/or the catheter 195.

Referring to FIG. 1B, an alternative exemplary embodiment of a medicalinstrument monitoring system 100 is shown. Herein, the medicalinstrument monitoring system 100 features a console 110 and a medicalinstrument 130 communicatively coupled to the console 110. For thisembodiment, the medical instrument 130 corresponds to a catheter, whichfeatures an integrated tubing with two or more lumen extending between aproximal end 131 and a distal end 132 of the integrated tubing. Theintegrated tubing (sometimes referred to as “catheter tubing”) is incommunication with one or more extension legs 140 via a bifurcation hub142. An optical-based catheter connector 144 may be included on aproximal end of at least one of the extension legs 140 to enable thecatheter 130 to operably connect to the console 110 via an interconnect145 or another suitable component. Herein, the interconnect 145 mayinclude a connector 146 that, when coupled to the optical-based catheterconnector 144, establishes optical connectivity between one or moreoptical fibers 147 (hereinafter, “optical fiber(s)”) included as part ofthe interconnect 145 and core fibers 137 deployed within the catheter130 and integrated into the tubing. Alternatively, a differentcombination of connectors, including one or more adapters, may be usedto optically connect the optical fiber(s) 147 to the core fibers 137within the catheter 130. The core fibers 137 deployed within thecatheter 130 as illustrated in FIG. 1B include the same characteristicsand perform the same functionalities as the core fibers 137 deployedwithin the stylet 120 of FIG. 1A.

The optical logic 180 is configured to support graphical rendering ofthe catheter 130, most notably the integrated tubing of the catheter130, based on characteristics of the reflected light signals 150received from the catheter 130. The characteristics may include shiftsin wavelength caused by strain on certain regions of the core fibers 137integrated within (or along) a wall of the integrated tubing, which maybe used to determine (through computation or extrapolation of thewavelength shifts) the physical state of the catheter 130, notably itsintegrated tubing or a portion of the integrated tubing such as a tip ordistal end of the tubing to read fluctuations (real-time movement) ofthe tip (or distal end).

More specifically, the optical logic 180 includes a light source 182.The light source 182 is configured to transmit the broadband incidentlight 155 for propagation over the optical fiber(s) 147 included in theinterconnect 145, which are optically connected to multiple core fibers137 within the catheter tubing. Herein, the optical receiver 184 isconfigured to: (i) receive returned optical signals, namely reflectedlight signals 150 received from optical fiber-based reflective gratings(sensors) fabricated within each of the core fibers 137 deployed withinthe catheter 130, and (ii) translate the reflected light signals 150into reflection data (from repository 192), namely data in the form ofelectrical signals representative of the reflected light signalsincluding wavelength shifts caused by strain. The reflected lightsignals 150 associated with different spectral widths include reflectedlight signals 151 provided from sensors positioned in the center corefiber (reference) of the catheter 130 and reflected light signals 152provided from sensors positioned in the outer core fibers of thecatheter 130, as described below.

As noted above, the shape sensing logic 194 is configured to comparewavelength shifts measured by sensors deployed in each outer core fiberat the same measurement region of the catheter (or same spectral width)to the wavelength shift at the center core fiber positioned alongcentral axis and operating as a neutral axis of bending. From theseanalytics, the shape sensing logic 190 may determine the shape the corefibers have taken in 3D space and may further determine the currentphysical state of the catheter 130 in 3D space for rendering on thedisplay 170.

According to one embodiment of the disclosure, the shape sensing logic194 may generate a rendering of the current physical state of thecatheter 130, especially the integrated tubing, based on heuristics orrun-time analytics. For example, the shape sensing logic 194 may beconfigured in accordance with machine-learning techniques to access adata store (library) with pre-stored data (e.g., images, etc.)pertaining to different regions of the catheter 130 in which the corefibers 137 experienced similar or identical wavelength shifts. From thepre-stored data, the current physical state of the catheter 130 may berendered. Alternatively, as another example, the shape sensing logic 194may be configured to determine, during run-time, changes in the physicalstate of each region of the catheter 130, notably the tubing, based onat least (i) resultant wavelength shifts experienced by the core fibers137 and (ii) the relationship of these wavelength shifts generated bysensors positioned along different outer core fibers at the samecross-sectional region of the catheter 130 to the wavelength shiftgenerated by a sensor of the center core fiber at the samecross-sectional region. It is contemplated that other processes andprocedures may be performed to utilize the wavelength shifts as measuredby sensors along each of the core fibers 137 to render appropriatechanges in the physical state of the catheter 130.

Referring to FIG. 2 , an exemplary embodiment of a structure of asection of the multi-core optical fiber included within the stylet 120of FIG. 1A is shown in accordance with some embodiments. The multi-coreoptical fiber section 200 of the multi-core optical fiber 135 depictscertain core fibers 137 ₁-137 _(M) (M≥2, M=4 as shown, see FIG. 3A)along with the spatial relationship between sensors (e.g., reflectivegratings) 210 ₁₁-210 _(NM) (N≥2; M≥2) present within the core fibers 137₁-137 _(M), respectively. As noted above, the core fibers 137 ₁-137 _(M)may be collectively referred to as “the core fibers 137.”

As shown, the section 200 is subdivided into a plurality ofcross-sectional regions 220 ₁-220 _(N), where each cross-sectionalregion 220 ₁-220 _(N) corresponds to reflective gratings 210 ₁₁-210 ₁₄ .. . 210 _(N1)-210 _(N4). Some or all of the cross-sectional regions 220₁ . . . 220 _(N) may be static (e.g., prescribed length) or may bedynamic (e.g., vary in size among the regions 220 ₁ . . . 220 _(N)). Afirst core fiber 137 ₁ is positioned substantially along a center(neutral) axis 230 while core fiber 137 ₂ may be oriented within thecladding of the multi-core optical fiber 135, from a cross-sectional,front-facing perspective, to be position on “top” the first core fiber137 ₁. In this deployment, the core fibers 137 ₃ and 137 ₄ may bepositioned “bottom left” and “bottom right” of the first core fiber 137₁. As examples, FIGS. 3A-4B provides illustrations of such.

Referencing the first core fiber 137 ₁ as an illustrative example, whenthe stylet 120 is operative, each of the reflective gratings 210 ₁-210_(N) reflects light for a different spectral width. As shown, each ofthe gratings 210 _(1i)-210 _(Ni) (1≤i≤M) is associated with a different,specific spectral width, which would be represented by different centerfrequencies of f₁ . . . f_(N), where neighboring spectral widthsreflected by neighboring gratings are non-overlapping according to oneembodiment of the disclosure.

Herein, positioned in different core fibers 137 ₂-137 ₃ but along at thesame cross-sectional regions 220-220 _(N) of the multi-core opticalfiber 135, the gratings 210 ₁₂-210 _(N2) and 210 ₁₃-210 _(N3) areconfigured to reflect incoming light at same (or substantially similar)center frequency. As a result, the reflected light returns informationthat allows for a determination of the physical state of the opticalfibers 137 (and the stylet 120) based on wavelength shifts measured fromthe returned, reflected light. In particular, strain (e.g., compressionor tension) applied to the multi-core optical fiber 135 (e.g., at leastcore fibers 137 ₂-137 ₃) results in wavelength shifts associated withthe returned, reflected light. Based on different locations, the corefibers 137 ₁-137 ₄ experience different types and degree of strain basedon angular path changes as the stylet 120 advances in the patient.

For example, with respect to the multi-core optical fiber section 200 ofFIG. 2 , in response to angular (e.g., radial) movement of the stylet120 is in the left-veering direction, the fourth core fiber 137 ₄ (seeFIG. 3A) of the multi-core optical fiber 135 with the shortest radiusduring movement (e.g., core fiber closest to a direction of angularchange) would exhibit compression (e.g., forces to shorten length). Atthe same time, the third core fiber 137 ₃ with the longest radius duringmovement (e.g., core fiber furthest from the direction of angularchange) would exhibit tension (e.g., forces to increase length). Asthese forces are different and unequal, the reflected light fromreflective gratings 210 _(N2) and 210 _(N3) associated with the corefibers 137 ₂ and 137 ₃ will exhibit different changes in wavelength. Thedifferences in wavelength shift of the reflected light signals 150 canbe used to extrapolate the physical configuration of the stylet 120 bydetermining the degrees of wavelength change caused bycompression/tension for each of the periphery fibers (e.g., the secondcore fiber 137 ₂ and the third core fiber 137 ₃) in comparison to thewavelength of the reference core fiber (e.g., first core fiber 137 ₁)located along the neutral axis 230 of the multi-core optical fiber 135.These degrees of wavelength change may be used to extrapolate thephysical state of the stylet 120. The reflected light signals 150 arereflected back to the console 110 via individual paths over a particularcore fiber 137 ₁-137 _(M).

Referring to FIG. 3A, a first exemplary embodiment of the stylet of FIG.1A supporting both an optical and electrical signaling is shown inaccordance with some embodiments. Herein, the stylet 120 features acentrally located multi-core optical fiber 135, which includes acladding 300 and a plurality of core fibers 137 ₁-137 _(M) (M≥2; M=4)residing within a corresponding plurality of lumens 320 ₁-320 _(M).While the multi-core optical fiber 135 is illustrated within four (4)core fibers 137 ₁-137 ₄, a greater number of core fibers 137 ₁-137 _(M)(M>4) may be deployed to provide a more detailed three-dimensionalsensing of the physical state (e.g., shape, etc.) of the multi-coreoptical fiber 135 and the stylet 120 deploying the optical fiber 135.

For this embodiment of the disclosure, the multi-core optical fiber 135is encapsulated within a concentric braided tubing 310 positioned over alow coefficient of friction layer 335. The braided tubing 310 mayfeature a “mesh” construction, in which the spacing between theintersecting conductive elements is selected based on the degree ofrigidity desired for the stylet 120, as a greater spacing may provide alesser rigidity, and thereby, a more pliable stylet 120.

According to this embodiment of the disclosure, as shown in FIGS. 3A-3B,the core fibers 137 ₁-137 ₄ include (i) a central core fiber 137 ₁ and(ii) a plurality of periphery core fibers 137 ₂-137 ₄, which aremaintained within lumens 320 ₁-320 ₄ formed in the cladding 300.According to one embodiment of the disclosure, one or more of the lumens320 ₁-320 ₄ may be configured with a diameter sized to be greater thanthe diameter of the core fibers 137 ₁-137 ₄. By avoiding a majority ofthe surface area of the core fibers 137 ₁-137 ₄ from being in directphysical contact with a wall surface of the lumens 320 ₁-320 ₄, thewavelength changes to the incident light are caused by angulardeviations in the multi-core optical fiber 135 thereby reducinginfluence of compression and tension forces being applied to the wallsof the lumens 320 ₁-320 _(M), not the core fibers 137 ₁-137 _(M)themselves.

As further shown in FIGS. 3A-3B, the core fibers 137 ₁-137 ₄ may includecentral core fiber 137 ₁ residing within a first lumen 320 ₁ formedalong the first neutral axis 230 and a plurality of core fibers 137₂-137 ₄ residing within lumens 320 ₂-320 ₄ each formed within differentareas of the cladding 300 radiating from the first neutral axis 230. Ingeneral, the core fibers 137 ₂-137 ₄, exclusive of the central corefiber 137 ₁, may be positioned at different areas within across-sectional area 305 of the cladding 300 to provide sufficientseparation to enable three-dimensional sensing of the multi-core opticalfiber 135 based on changes in wavelength of incident light propagatingthrough the core fibers 137 ₂-137 ₄ and reflected back to the consolefor analysis.

For example, where the cladding 300 features a circular cross-sectionalarea 305 as shown in FIG. 3B, the core fibers 137 ₂-137 ₄ may bepositioned substantially equidistant from each other as measured along aperimeter of the cladding 300, such as at “top” (12 o'clock),“bottom-left” (8 o'clock) and “bottom-right” (4 o'clock) locations asshown. Hence, in general terms, the core fibers 137 ₂-137 ₄ may bepositioned within different segments of the cross-sectional area 305.Where the cross-sectional area 305 of the cladding 300 has a distal tip330 and features a polygon cross-sectional shape (e.g., triangular,square, rectangular, pentagon, hexagon, octagon, etc.), the central corefiber 137 ₁ may be located at or near a center of the polygon shape,while the remaining core fibers 137 ₂-137 _(M) may be located proximateto angles between intersecting sides of the polygon shape.

Referring still to FIGS. 3A-3B, operating as the conductive medium forthe stylet 120, the braided tubing 310 provides mechanical integrity tothe multi-core optical fiber 135 and operates as a conductive pathwayfor electrical signals. For example, the braided tubing 310 may beexposed to a distal tip of the stylet 120. The cladding 300 and thebraided tubing 310, which is positioned concentrically surrounding acircumference of the cladding 300, are contained within the sameinsulating layer 350. The insulating layer 350 may be a sheath orconduit made of protective, insulating (e.g., non-conductive) materialthat encapsulates both for the cladding 300 and the braided tubing 310,as shown.

Referring to FIG. 4A, a second exemplary embodiment of the stylet ofFIG. 1A is shown in accordance with some embodiments. Referring now toFIG. 4A, a second exemplary embodiment of the stylet 120 of FIG. 1Asupporting both an optical and electrical signaling is shown. Herein,the stylet 120 features the multi-core optical fiber 135 described aboveand shown in FIG. 3A, which includes the cladding 300 and the firstplurality of core fibers 137 ₁-137 _(M) (M≥3; M=4 for embodiment)residing within the corresponding plurality of lumens 320 ₁-320 _(M).For this embodiment of the disclosure, the multi-core optical fiber 135includes the central core fiber 137 ₁ residing within the first lumen320 ₁ formed along the first neutral axis 230 and the second pluralityof core fibers 137 ₂-137 ₄ residing within corresponding lumens 320₂-320 ₄ positioned in different segments within the cross-sectional area305 of the cladding 300. Herein, the multi-core optical fiber 135 isencapsulated within a conductive tubing 400. The conductive tubing 400may feature a “hollow” conductive cylindrical member concentricallyencapsulating the multi-core optical fiber 135.

Referring to FIGS. 4A-4B, operating as a conductive medium for thestylet 120 in the transfer of electrical signals (e.g., ECG signals) tothe console, the conductive tubing 400 may be exposed up to a tip 410 ofthe stylet 120. For this embodiment of the disclosure, a conductiveepoxy 420 (e.g., metal-based epoxy such as a silver epoxy) may beaffixed to the tip 410 and similarly joined with atermination/connection point created at a proximal end 430 of the stylet120. The cladding 300 and the conductive tubing 400, which is positionedconcentrically surrounding a circumference of the cladding 300, arecontained within the same insulating layer 440. The insulating layer 440may be a protective conduit encapsulating both for the cladding 300 andthe conductive tubing 400, as shown.

Referring to FIG. 5A, an elevation view of a first illustrativeembodiment of a catheter including integrated tubing, a diametricallydisposed septum, and micro-lumens formed within the tubing and septum isshown in accordance with some embodiments. Herein, the catheter 130includes integrated tubing, the diametrically disposed septum 510, andthe plurality of micro-lumens 530 ₁-530 ₄ which, for this embodiment,are fabricated to reside within the wall 500 of the integrated tubing ofthe catheter 130 and within the septum 510. In particular, the septum510 separates a single lumen, formed by the inner surface 505 of thewall 500 of the catheter 130, into multiple lumens, namely two lumens540 and 545 as shown. Herein, the first lumen 540 is formed between afirst arc-shaped portion 535 of the inner surface 505 of the wall 500forming the catheter 130 and a first outer surface 555 of the septum 510extending longitudinally within the catheter 130. The second lumen 545is formed between a second arc-shaped portion 565 of the inner surface505 of the wall 500 forming the catheter 130 and a second outer surfaces560 of the septum 510.

According to one embodiment of the disclosure, the two lumens 540 and545 have approximately the same volume. However, the septum 510 need notseparate the tubing into two equal lumens. For example, instead of theseptum 510 extending vertically (12 o'clock to 6 o'clock) from afront-facing, cross-sectional perspective of the tubing, the septum 510could extend horizontally (3 o'clock to 9 o'clock), diagonally (1o'clock to 7 o'clock; 10 o'clock to 4 o'clock) or angularly (2 o'clockto 10 o'clock). In the later configuration, each of the lumens 540 and545 of the catheter 130 would have a different volume.

With respect to the plurality of micro-lumens 530 ₁-530 ₄, the firstmicro-lumen 530 ₁ is fabricated within the septum 510 at or near thecross-sectional center 525 of the integrated tubing. For thisembodiment, three micro-lumens 530 ₂-530 ₄ are fabricated to residewithin the wall 500 of the catheter 130. In particular, a secondmicro-lumen 530 ₂ is fabricated within the wall 500 of the catheter 130,namely between the inner surface 505 and outer surface 507 of the firstarc-shaped portion 535 of the wall 500. Similarly, the third micro-lumen530 ₃ is also fabricated within the wall 500 of the catheter 130, namelybetween the inner and outer surfaces 505/507 of the second arc-shapedportion 555 of the wall 500. The fourth micro-lumen 530 ₄ is alsofabricated within the inner and outer surfaces 505/507 of the wall 500that are aligned with the septum 510.

According to one embodiment of the disclosure, as shown in FIG. 5A, themicro-lumens 530 ₂-530 ₄ are positioned in accordance with a “top-left”(10 o'clock), “top-right” (2 o'clock) and “bottom” (6 o'clock) layoutfrom a front-facing, cross-sectional perspective. Of course, themicro-lumens 530 ₂-530 ₄ may be positioned differently, provided thatthe micro-lumens 530 ₂-530 ₄ are spatially separated along thecircumference 520 of the catheter 130 to ensure a more robust collectionof reflected light signals from the outer core fibers 570 ₂-570 ₄ wheninstalled. For example, two or more of micro-lumens (e.g., micro-lumens530 ₂ and 530 ₄) may be positioned at different quadrants along thecircumference 520 of the catheter wall 500.

Referring to FIG. 5B, a perspective view of the first illustrativeembodiment of the catheter of FIG. 5A including core fibers installedwithin the micro-lumens is shown in accordance with some embodiments.According to one embodiment of the disclosure, the second plurality ofmicro-lumens 530 ₂-530 ₄ are sized to retain corresponding outer corefibers 570 ₂-570 ₄, where the diameter of each of the second pluralityof micro-lumens 530 ₂-530 ₄ may be sized just larger than the diametersof the outer core fibers 570 ₂-570 ₄. The size differences between adiameter of a single core fiber and a diameter of any of the micro-lumen530 ₁-530 ₄ may range between 0.001 micrometers (μm) and 1000 μm, forexample. As a result, the cross-sectional areas of the outer core fibers570 ₂-570 ₄ would be less than the cross-sectional areas of thecorresponding micro-lumens 530 ₂-530 ₄. A “larger” micro-lumen (e.g.,micro-lumen 530 ₂) may better isolate external strain being applied tothe outer core fiber 570 ₂ from strain directly applied to the catheter130 itself. Similarly, the first micro-lumen 530 ₁ may be sized toretain the center core fiber 570 ₁, where the diameter of the firstmicro-lumen 530 ₁ may be sized just larger than the diameter of thecenter core fiber 570 ₁.

As an alternative embodiment of the disclosure, one or more of themicro-lumens 530 ₁-530 ₄ may be sized with a diameter that exceeds thediameter of the corresponding one or more core fibers 570 ₁-570 ₄.However, at least one of the micro-lumens 530 ₁-530 ₄ is sized tofixedly retain their corresponding core fiber (e.g., core fiber retainedwith no spacing between its lateral surface and the interior wallsurface of its corresponding micro-lumen). As yet another alternativeembodiment of the disclosure, all the micro-lumens 530 ₁-530 ₄ are sizedwith a diameter to fixedly retain the core fibers 570 ₁-570 ₄.

Referring to FIGS. 6A-6B, flowcharts of methods of operations conductedby the medical instrument monitoring system of FIGS. 1A-1B to achieveoptic 3D shape sensing are shown in accordance with some embodiments.Herein, the catheter includes at least one septum spanning across adiameter of the tubing wall and continuing longitudinally to subdividethe tubing wall. The medial portion of the septum is fabricated with afirst micro-lumen, where the first micro-lumen is coaxial with thecentral axis of the catheter tubing. The first micro-lumen is configuredto retain a center core fiber. Two or more micro-lumen, other than thefirst micro-lumen, are positioned at different locationscircumferentially spaced along the wall of the catheter tubing. Forexample, two or more of the second plurality of micro-lumens may bepositioned at different quadrants along the circumference of thecatheter wall.

Furthermore, each core fiber includes a plurality of sensors spatiallydistributed along its length between at least the proximal and distalends of the catheter tubing. This array of sensors is distributed toposition sensors at different regions of the core fiber to enabledistributed measurements of strain throughout the entire length or aselected portion of the catheter tubing. These distributed measurementsmay be conveyed through reflected light of different spectral widths(e.g., specific wavelength or specific wavelength ranges) that undergoescertain wavelength shifts based on the type and degree of strain.

According to one embodiment of the disclosure, as shown in FIG. 6A, foreach core fiber, broadband incident light is supplied to propagatethrough a particular core fiber (block 600). Unless discharged, upon theincident light reaching a sensor of a distributed array of sensorsmeasuring strain on a particular core fiber, light of a prescribedspectral width associated with the first sensor is to be reflected backto an optical receiver within a console (blocks 605-610). Herein, thesensor alters characteristics of the reflected light signal to identifythe type and degree of strain on the particular core fiber as measuredby the first sensor (blocks 615-620). According to one embodiment of thedisclosure, the alteration in characteristics of the reflected lightsignal may signify a change (shift) in the wavelength of the reflectedlight signal from the wavelength of the incident light signal associatedwith the prescribed spectral width. The sensor returns the reflectedlight signal over the core fiber and the remaining spectrum of theincident light continues propagation through the core fiber toward adistal end of the catheter tubing (blocks 625-630). The remainingspectrum of the incident light may encounter other sensors of thedistributed array of sensors, where each of these sensors would operateas set forth in blocks 605-630 until the last sensor of the distributedarray of sensors returns the reflected light signal associated with itsassigned spectral width and the remaining spectrum is discharged asillumination.

Referring now to FIG. 6B, during operation, multiple reflected lightsignals are returned to the console from each of the plurality of corefibers residing within the corresponding plurality of micro-lumensformed within a catheter, such as the catheter of FIG. 1B. Inparticular, the optical receiver receives reflected light signals fromthe distributed arrays of sensors located on the center core fiber andthe outer core fibers and translates the reflected light signals intoreflection data, namely electrical signals representative of thereflected light signals including wavelength shifts caused by strain(blocks 650-655). The reflection data classification logic is configuredto identify which core fibers pertain to which reflection data andsegregate reflection data provided from reflected light signalspertaining to a particular measurement region (or similar spectralwidth) into analysis groups (block 660-665).

Each analysis group of reflection data is provided to shape sensinglogic for analytics (block 670). Herein, the shape sensing logiccompares wavelength shifts at each outer core fiber with the wavelengthshift at the center core fiber positioned along central axis andoperating as a neutral axis of bending (block 675). From theseanalytics, on all analytic groups (e.g., reflected light signals fromsensors in all or most of the core fibers), the shape sensing logic maydetermine the shape the core fibers have taken in three-dimensionalspace, from which the shape sensing logic can determine the currentphysical state of the catheter in three-dimension space (blocks680-685).

Referring to FIG. 7 , an exemplary embodiment of the medical instrumentmonitoring system of FIG. 1A during operation and insertion of thecatheter into a patient are shown in accordance with some embodiments.Herein, the catheter 195 generally includes integrated tubing with aproximal portion 720 that generally remains exterior to the patient 700and a distal portion 730 that generally resides within the patientvasculature after placement is complete, where the catheter 195 entersthe vasculature at insertion site 710. The stylet 120 may be advancedthrough the catheter 195 to a desired position within the patientvasculature such that a distal end (or tip) 735 of the stylet 120 (andhence a distal end of the catheter 195) is proximate the patient'sheart, such as in the lower one-third (⅓) portion of the Superior VenaCava (“SVC”) for example. For this embodiment, various instruments maybe placed at the distal end 735 of the stylet 120 and/or the catheter195 to measure pressure of blood in a certain heart chamber and in theblood vessels, view an interior of blood vessels, or the like.

The console connector 133 enables the stylet 120 to be operablyconnected to the console 110 via the interconnect 145 (FIG. 1A). Herein,the connector 146 is configured to engage (mate) with the consoleconnector 133 to allow for the propagation of light between the console110 and the stylet assembly 119 (particularly the stylet 120) as well asthe propagation of electrical signals from the stylet 120 to the console110

During advancement of the stylet 120, the distal tip 735 typicallyfluctuates due to, among other factors, blood flow and blood pressurewithin the blood vessel. These fluctuations may be movements by a distalportion of the stylet 120 in any direction. Typically, the movements arerelatively minor compared to the overall advancement of the stylet 120(and the catheter 195); however, such movements are detectable by thesensors of the core fibers integrated into the stylet 120.

The fluctuations may vary based on the blood vessel in which the stylet120 (and catheter 195) is advancing due to one or more of the physicalproperties of the blood vessel, the location of the blood vessel (andits proximity to the patient's heart), and any defects affecting theblood vessel (e.g., vessel constriction, vasospasm, occlusion, etc.). Aswill be discussed in further detail below, the volume of the bloodvessel may affect the fluctuations (e.g., a larger diameter may providefor greater fluctuation). Similarly, the turbulence of the blood flowgenerally affects the fluctuations (e.g., higher turbulence typicallyequates to greater fluctuation). Relatedly, the proximity of the distaltip 735 to the patient's heart may affect the fluctuations due to theturbulent blood flow emanating from the right atrium of the heart andflowing through the SVC (see FIG. 8A). The blood pressure within theblood vessel may also affect tip fluctuations. Further, various defectsmay affect the fluctuations of the distal tip 735 and cause fluctuationsthat vary from those expected when the stylet 120 is advancing through ahealthy blood vessel. FIGS. 8B-8D provide examples of the stylet 120advancing toward various defects.

Referring now to FIG. 8A, a detailed view of a stylet disposed withinthe Superior Vena Cava (SVC) advancing toward the right atrium of apatient is shown in accordance with some embodiments. FIG. 8Aillustrates a detailed perspective of the vasculature proximate to theheart 803 of a patient as well as the anatomy of the heart 803.Specifically, as the stylet 120 approaches the right atrium 804 throughthe SVC 800, the stylet 120 may either advance into the right atrium 804or into the azygos vein 802. The stylet 120 is often used to locate aparticular point in the vasculature at which point the catheter 195 maybe used to administer a medical procedure or medicament, where thispoint may be referred to as the “target site” 805.

In some embodiments, the tip fluctuation logic 198 is configured toconfirm the location of the distal tip 735 of the stylet 120 (which, inturn, corresponds to the distal tip of the catheter 195, within apredetermined distance such as approximately 1-2 cm) as the catheter 195and the stylet 120 advance through a patient's vasculature toward atarget site 805. According to one embodiment of the disclosure, the tipfluctuation logic 198 is configured to analyze a subset of thewavelength shifts measured by sensors deployed in each of the corefibers 137, for example, the sensors included in the distal portion 801of the stylet 120. In some embodiments, the distal portion 801 includesa plurality of sensors such as 50, 30, 10, 5, 3, etc. It should be notedthat the disclosure is not limited to the recited number of sensors andsuch a recitation should be understood to merely provide exemplaryexamples. Further, in some embodiments, the number of sensors includedin the distal portion 501 and thus utilized by the tip fluctuation logic198 may be dynamically configurable during run-time. Thus, a user mayprovide user input to the console 110 to adjust the number of sensorsutilized by the tip fluctuation logic 198. As a result, a user may alterthe specificity of the analysis performed by the tip fluctuation logic198 during run-time (e.g., where utilization of a fewer number ofsensors may correspond to an analysis that is more specific as tofluctuation at the distal tip 735).

In particular, the tip fluctuation logic 198 is configured to analyzewavelength shifts measured by the sensors of core fibers 137 locatedwithin the distal portion 801, where such corresponds to a tipfluctuation analysis as discussed above. With reference to FIG. 8A, asthe distal tip 735 of the stylet 120 advances through the SVC 800 towardthe target site 805 within the right atrium 804, the sensors within thedistal portion 801 may detect an increase in movements, corresponding toan increase in tip fluctuations. The increase in tip fluctuations may becaused by the turbulence of the blood flow exiting the right atrium andentering the SVC (thus, the stylet 120 is advancing in a directionopposing the blood flow). Thus, the increase in fluctuations may providethe tip fluctuation logic 198 one indication that the distal tip 735 isapproaching the right atrium 804.

In one embodiment, the tip fluctuation logic 198 may be configured tocorrelate the wavelength shifts received from the sensors within thedistal portion 801 with data from the experiential knowledge repository193 corresponding to previously detected wavelength shifts received fromsensors within a similar distal portion of a stylet. Based on thecorrelation, the tip fluctuation logic 198 may determine the distal tip735 is within the SVC 800, within a certain distance to the right atrium804 or the target site 805, or within the right atrium 804. In oneinstance, the determination may be based on whether the correlationresults indicate that the correlation between the detected wavelengthshifts and any of the previously detected wavelength shiftscorresponding to the SVC 800, the target site 805 or the right atrium804 is greater than or equal to a threshold.

In other embodiments, the detected wavelength shifts received from thesensors within the distal portion 801 may be utilized by the tipfluctuation logic 198 as input to a trained machine-learning model that,upon processing, provides a correlation to one or more of previouslydetected fluctuations corresponding to the SVC 800, the target site 805or the right atrium 804. A similar threshold determination may then bemade by the tip fluctuation logic 198 as referenced above.

In embodiments in which ECG signals may be obtained by the stylet 120(or the catheter 195), the ECG signals may provide an indication as tothe rhythmic pulses of the heart 803. The tip fluctuation logic 198 maycompare the rhythmic pulses as indicated by the ECG signals to thedetected wavelength shifts received from the sensors within the distalportion 801 to determine whether the detected wavelength shifts indicatemovement that correlates to the rhythmic pulses by at least a threshold.

In some embodiments, the tip confirmation may be used in combinationwith the shape sensing functionality discussed above in which the shapesensing logic 194 determines the current physical state of the stylet120 (and hence the catheter 195) in 3D space for rendering on thedisplay 170. Further, in some embodiments, the catheter 195 and/or thestylet 120 may incorporate a pressure sensor configured to detect theblood pressure within the blood vessel (or heart chamber) in which thedistal tip 735 is placed. The detected blood pressure may also beutilized in the correlations discussed herein such that the tipfluctuation logic 198 may correlate the detected blood pressure withpreviously detected blood pressures to aid in the determination of theplacement of the distal tip 735 and/or detection of a defect affectingthe blood vessel.

In some embodiments, the tip fluctuation logic 198 may detect, orprovide data for detection of, placement of the distal tip 735 in theAzygos vein 802. For instance, the tip fluctuation logic 198 may detectfluctuations correlating to placement within the SVC 800 andsubsequently detect a decrease in fluctuations such that the detectedfluctuations no longer correlate to placement with the SVC 800 butinstead correlate to placement within the Azygos vein 802. For example,upon detection of a decrease in fluctuations, the tip fluctuation logic198 may perform a correlation between the detected fluctuations andpreviously detected fluctuations known to correspond to the Azygos vein.The decrease in fluctuations of the distal tip 735 within the Azygosvein compared to the within the SVC 800 may be due to the smallerdiameter of the Azygos vein 802, and less turbulent blood flow withinthe Azygos vein 802. This detection may be optionally confirmed throughdetection of the direction of blood flow. Specifically, if the distaltip 735 of the stylet 120 advances into the Azygos vein 802, the stylet120 will be advancing in the direction of blood flow indicating that thestylet 120 has deviated from the SVC 800.

In some embodiments, the tip fluctuation logic 198 may generate agraphic illustrating the detected tip fluctuation compared to previouslydetected tip fluctuations and/or the rhythmic impulses of the heart. Inone embodiment, such a graphic may include a dynamic visualization ofthe present distal tip moving in accordance with the detected tipfluctuations adjacent to a distal tip moving in accordance withpreviously detected tip fluctuations.

Referring to FIGS. 8B-8D, diagrams are provided illustrating the stylet120 advancing through a vessel of the vasculature of a patient andencountering a defect affecting the vessel. The stylet 120 may beadvancing through the vessel within the catheter 195 (not shown forpurposes of clarity). Referring specifically to FIG. 8B, a sideelevation of the stylet 120 advancing through a vessel of thevasculature of a patient toward a point of constriction in the vessel isshown in accordance with some embodiments. The stylet 120 is shownadvancing through the vessel 814 toward a point of constriction 815,which may be a vasoconstriction, e.g., the constriction of capillariesor arterioles. In some embodiments, the vasoconstriction may result inelevated blood pressure levels.

As the stylet 120 advances through the vessel 814, the console 110receives reflected light from sensors located along the core fibers 137.As discussed above, the tip fluctuation logic 198 may perform ananalysis on the wavelength shifts detected by a subset of the sensors,particularly those disposed in a distal portion of the stylet 120 (suchas those disposed in the distal portion 801 of FIG. 8A). As the stylet120 advances toward the point of constriction 815, the fluctuations ofthe distal tip 735 change due to properties of the blood vessel such asa narrowing diameter and a decrease in blood flow. Thus, by monitoringthe tip fluctuations of the distal tip 735 during advancement, the tipfluctuation logic 198 may detect an unexpected change (decrease) in thetip fluctuations (e.g., a change not based on entrance into a newvessel). The tip fluctuation logic 198 may then correlate the detectedwavelength shifts corresponding to the decrease in fluctuations withpreviously detected wavelength shifts for various defects that affectblood vessels (e.g., the defect being a vasoconstriction in FIG. 8B).The correlation may be performed in any manner as discussed hereinincluding, for example, via a machine-learning model.

When the tip fluctuation logic 198 determines the result of thecorrelation is above a threshold, an alert or notification may begenerated and provided to the user. The alert or notification mayaudible or visual, and may be displayed on the display 170 of theconsole 110. In some embodiments, the shape sensing functionalities ofthe shape sensing logic 194 discussed above may be combined with thecorrelation performed by the tip fluctuation logic 198 to provide anindication of a location of the point of constriction 815 (or otherdefect discussed below) to the user.

Referring to FIG. 8C, side elevation of a stylet advancing through avessel of the vasculature of a patient toward a vasospasm affecting thevessel is shown in accordance with some embodiments. The stylet 120 isshown advancing through the vessel 816 toward a vasospasm 817, which maybe due to an arterial spasm. As the stylet 120 advances through thevessel 816, the console 110 receives reflected light from sensorslocated along the core fibers 137. As the stylet 120 advances toward thevasospasm 817, the fluctuations of the distal tip 735 change due toproperties of the blood vessel such as a narrowing diameter and adecrease in blood flow therein. Thus, by monitoring the tip fluctuationsof the distal tip 735 during advancement, the tip fluctuation logic 198may detect an unexpected change (increase due to the spasm, e.g.,contractions, of the walls of the vessel) in the tip fluctuations (e.g.,a change not based on entrance into a new vessel). The tip fluctuationlogic 198 may then correlate the detected wavelength shiftscorresponding to the decrease in fluctuations with previously detectedwavelength shifts for various defects that affect blood vessels (e.g.,the defect being a vasospasm in FIG. 8C). The correlation may beperformed in any manner as discussed herein including, for example, viaa machine-learning model. Alerts or notifications may be generated in asimilar manner as discussed above.

Referring to FIG. 8D, a side elevation of a stylet advancing through avessel of the vasculature of a patient toward an occlusion in the vesselis shown in accordance with some embodiments. The stylet 120 is shownadvancing through the vessel 818 toward an occlusion 819, e.g., ablockage or clot due to plague build-up, a blood clot, etc. As thestylet 120 advances through the vessel 818, the console 110 receivesreflected light from sensors located along the core fibers 137. As thestylet 120 advances toward the occlusion 819, the fluctuations of thedistal tip 735 change due to properties of the blood vessel such as anarrowing diameter and a decrease in blood flow therein. Thus, bymonitoring the tip fluctuations of the distal tip 735 duringadvancement, the tip fluctuation logic 198 may detect an unexpectedchange (decrease) in the tip fluctuations (e.g., a change not based onentrance into a new vessel). The tip fluctuation logic 198 may thencorrelate the detected wavelength shifts corresponding to the decreasein fluctuations with previously detected wavelength shifts for variousdefects that affect blood vessels (e.g., the defect being an occlusionin FIG. 8D). The correlation may be performed in any manner as discussedherein including, for example, via a machine-learning model.Additionally, with respect to advancement of the stylet 120 toward theocclusion 819, the distal tip 735 may come into contact with theocclusion 819 thereby causing the fluctuations to cease. Therefore,detection that fluctuations have ceased may be a factor in thecorrelation performed by the tip fluctuation logic 198. Alerts ornotifications may be generated in a similar manner as discussed above.

While some particular embodiments have been disclosed herein, and whilethe particular embodiments have been disclosed in some detail, it is notthe intention for the particular embodiments to limit the scope of theconcepts provided herein. Additional adaptations and/or modificationscan appear to those of ordinary skill in the art, and, in broaderaspects, these adaptations and/or modifications are encompassed as well.Accordingly, departures may be made from the particular embodimentsdisclosed herein without departing from the scope of the conceptsprovided herein.

What is claimed is:
 1. A medical device system for detecting fluctuationusing optical fiber technology of a medical device, the systemcomprising: the medical device comprising an optical fiber having one ormore core fibers, each of the one or more core fibers including aplurality of sensors distributed along a longitudinal length of acorresponding core fiber and each sensor of the plurality of sensorsbeing configured to (i) reflect a light signal of a different spectralwidth based on received incident light, and (ii) change a characteristicof the reflected light signal based on strain experienced by the opticalfiber; and a console including one or more processors and anon-transitory computer-readable medium having stored thereon logic,when executed by the one or more processors, causes operationsincluding: providing a broadband incident light signal to the opticalfiber; receiving reflected light signals of different spectral widths ofthe broadband incident light signal by one or more of the plurality ofsensors; processing the reflected light signals associated with the oneor more core fibers to detect fluctuations of a portion of the opticalfiber; and determining a location of the portion of the optical fiber ora defect affecting a vessel in which the portion is disposed based onthe detected fluctuations.
 2. The system of claim 1, wherein the portionof the optical fiber is a distal tip.
 3. The system of claim 1, whereinthe optical fiber is a multi-core optical fiber including a plurality ofcore fibers.
 4. The system of claim 1, wherein the defect is selectedfrom the group consisting of a constriction of the vessel, a vasospasmof the vessel, and an occlusion in the vessel.
 5. The system of claim 1,wherein the determining includes: correlating the reflected lightsignals with previously obtained reflected light signals to identify thelocation of the portion of the optical fiber or the defect affecting thevessel, and determining whether a correlation result is above a firstthreshold.
 6. The system of claim 5, wherein the correlating isperformed through machine-learning techniques.
 7. The system of claim 1,wherein determining the location of the portion of the optical fiberincludes: obtaining electrocardiogram (ECG) signals, correlating the ECGsignals with the detected fluctuations to identify whether the detectedfluctuations include movements in accordance with a rhythmic pattern ofthe ECG signals, and determining whether a correlation result is above afirst threshold.
 8. The system of claim 1, wherein the medical device isone of an introducer wire, a guidewire, a stylet, a stylet within aneedle, a needle with the optical fiber inlayed into a cannula of theneedle or a catheter with the optical fiber inlayed into one or morewalls of the catheter.
 9. The system of claim 1, wherein each of theplurality of sensors is a reflective grating, where each reflectivegrating alters its reflected light signal by applying a wavelength shiftdependent on a strain experienced by the reflective grating.
 10. Thesystem of claim 1, wherein the logic, when executed by the one or moreprocessors, causes further operations including generating an alertindicating an existence of the defect.
 11. The system of claim 10,wherein the alert includes an indication of a location of the defect.12. A method for placing a medical device into a body of a patient, themethod comprising: providing a broadband incident light signal to anoptical fiber included within the medical device, wherein the opticalfiber includes one or more core fibers, each of the one or more corefibers including a plurality of reflective gratings distributed along alongitudinal length of a corresponding core fiber and each of theplurality of reflective gratings being configured to (i) reflect a lightsignal of a different spectral width based on received incident light,and (ii) change a characteristic of the reflected light signal based onstrain experienced by the optical fiber; receiving reflected lightsignals of different spectral widths of the broadband incident lightsignal by one or more of a plurality of sensors; processing thereflected light signals associated with the one or more core fibers todetect fluctuations of a portion of the optical fiber; and determining alocation of the portion of the optical fiber or a defect affecting avessel in which the portion is disposed based on the detectedfluctuations.
 13. The method of claim 12, wherein the portion of theoptical fiber is a distal tip.
 14. The method of claim 12, wherein theoptical fiber is a multi-core optical fiber including a plurality ofcore fibers.
 15. The method of claim 12, wherein the defect is selectedfrom the group consisting of a constriction of the vessel, a vasospasmof the vessel, and an occlusion in the vessel.
 16. The method of claim12, wherein the determining includes: correlating the reflected lightsignals with previously obtained reflected light signals to identify thelocation of the portion of the optical fiber or the defect affecting thevessel; and determining whether a correlation result is above a firstthreshold.
 17. The method of claim 16, wherein the correlating isperformed through machine-learning techniques.
 18. The method of claim12, wherein determining the location of the portion of the optical fiberincludes: obtaining electrocardiogram (ECG) signals; correlating the ECGsignals with the detected fluctuations to identify whether the detectedfluctuations include movements in accordance with a rhythmic pattern ofthe ECG signals; and determining whether a correlation result is above afirst threshold.
 19. The method of claim 12, wherein the medical deviceis one of an introducer wire, a guidewire, a stylet, a stylet within aneedle, a needle with the optical fiber inlayed into a cannula of theneedle or a catheter with the optical fiber inlayed into one or morewalls of the catheter.
 20. The method of claim 12, wherein each of theplurality of sensors is a reflective grating, wherein each reflectivegrating alters its reflected light signal by applying a wavelength shiftdependent on a strain experienced by the reflective grating.
 21. Themethod of claim 12, wherein the logic, when executed by the one or moreprocessors, causes further operations including generating an alertindicating an existence of the defect.
 22. The method of claim 21,wherein the alert includes an indication of a location of the defect.23. A non-transitory computer-readable medium having stored thereonlogic that, when executed by one or more processors, causes operationsincluding: providing a broadband incident light signal to an opticalfiber included within a medical device, wherein the optical fiberincludes one or more core fibers, each of the one or more core fibersincluding a plurality of reflective gratings distributed along alongitudinal length of a corresponding core fiber and each of theplurality of reflective gratings being configured to (i) reflect a lightsignal of a different spectral width based on received incident light,and (ii) change a characteristic of the reflected light signal based onstrain experienced by the optical fiber; receiving reflected lightsignals of different spectral widths of the broadband incident lightsignal by one or more of the plurality of sensors; processing thereflected light signals associated with the one or more core fibers todetect fluctuations of a portion of the optical fiber; and determining alocation of the portion of the optical fiber or a defect affecting avessel in which the portion is disposed based on the detectedfluctuations.
 24. The non-transitory, computer-readable medium of claim23, wherein the portion of the optical fiber is a distal tip.
 25. Thenon-transitory, computer-readable medium of claim 23, wherein theoptical fiber is a multi-core optical fiber including a plurality ofcore fibers.
 26. The non-transitory, computer-readable medium of claim23, wherein the defect is selected from the group consisting of aconstriction of the vessel, a vasospasm of the vessel, and an occlusionin the vessel.
 27. The non-transitory, computer-readable medium of claim23, wherein the determining includes: correlating the reflected lightsignals with previously obtained reflected light signals to identify thelocation of the portion of the optical fiber or the defect affecting thevessel; and determining whether a correlation result is above a firstthreshold.
 28. The non-transitory, computer-readable medium of claim 27,wherein the correlating is performed through machine-learningtechniques.
 29. The non-transitory, computer-readable medium of claim23, wherein determining the location of the portion of the optical fiberincludes: obtaining electrocardiogram (ECG) signals; correlating the ECGsignals with the detected fluctuations to identify whether the detectedfluctuations include movements in accordance with a rhythmic pattern ofthe ECG signals; and determining whether a correlation result is above afirst threshold.
 30. The non-transitory, computer-readable medium ofclaim 23, wherein the medical device is one of an introducer wire, aguidewire, a stylet, a stylet within a needle, a needle with the opticalfiber inlayed into a cannula of the needle or a catheter with theoptical fiber inlayed into one or more walls of the catheter.
 31. Thenon-transitory, computer-readable medium of claim 23, wherein each ofthe plurality of sensors is a reflective grating, wherein eachreflective grating alters its reflected light signal by applying awavelength shift dependent on a strain experienced by the reflectivegrating.
 32. The non-transitory, computer-readable medium of claim 23,wherein the logic, when executed by the one or more processors, causesfurther operations including generating an alert indicating an existenceof the defect.
 33. The non-transitory, computer-readable medium of claim23, wherein the alert includes an indication of a location of thedefect.